Dr. Ichihara is a middle-aged scientist heading the Cybergenic Research Institute for the Ministry of Defense, specializing in cybernetic enhancement technology. He possesses deep understanding of cybernetic systems and actively seeks volunteers from the Special Security Force for experimental procedures, facing initial resistance from Chief Taki who prohibits agent participation. After agent Raiden sustains life-threatening injuries—including multiple spinal fractures and paralysis—during a counter-terrorism operation, Ichihara intervenes. He proposes cybernetic reconstruction as the sole viable solution. Raiden consents, undergoing transformation into a highly capable cyborg with enhanced strength, combat proficiency, and resistance to conventional weaponry.

Ichihara later becomes a critical target as a witness to the H-File, a covert political conspiracy involving corrupt officials permitting illegal nuclear waste disposal in Hokkaido. During an assault on his facility by corrupt special forces and the psychic antagonist Lucifer, he actively monitors Raiden's defensive efforts, expressing visible satisfaction at Raiden's effectiveness in neutralizing attackers. His concern grows when Raiden fails to defeat Lucifer. While recovering from injuries in the generator room, Lucifer uses telekinesis to locate Ichihara via surveillance systems and triggers an explosion in his computer console, causing his death. His work and actions directly influence the trajectory of key characters and the resolution of the central conflict.